The present invention relates to an improved appliance for instruction in a physics lab, particularly concerning an apparatus for determining the acceleration of an object under gravity which is improved with a digital timer, an angle adjusting and displaying device, and an electrical control device for obtaining more precise results. This improvement has operational and economic advantages over prior art devices.
In a physics lab, to obtain the value of various physical constants, and to establish the principles and laws of physics, several experimental instruments and steps are required. It is first necessary to give a precise meaning to each physical term used and to fix a unit of measurement for it. Instruments can be constructed to measure the physical quantities involved in a particular effect, and it may be finally determined from these measurements the relation which exists between those various quantities. The limit of validity of these laws is determined by the degree of precision attained in the measurements. In many instances improved measurements have indicated departures from previously established principles and have led to refinements in the laws or even to entirely new discoveries.
To find out the acceleration of a moving object under gravity is firstly to get a plurality of data concerning the time intervals during which the moving object passes through various predetermined distances, and then from the data of the time intervals and the distances, to calculate the acceleration of the moving object. The conventional appliances used in prior methods for obtaining the time interval data are complicated in their data-collecting operation and ensue discouraging errors in the practical results of the lab experiment.